Technical Field
The present disclosure relates to power tools and, more particularly, to a muffler for a pneumatic power tool.
Background of Related Art
Pneumatic power tools, e.g., ratchets, drills, wrenches, grinders, sanders, and the like, are commonly used in industrial and residential settings. Such tools typically include a hollow handle defining a chamber that provides an inlet and exit conduit for the high pressure air that powers the tool motor. The chamber includes an air intake passage and an air exhaust passage. Each passage extends between the motor and an opening in or near the bottom surface of the handle. The portion of the intake passage located near the handle opening typically includes a standard air coupler or the like. The coupler is adapted to connect to a pressurized air source. The exhaust passage typically opens to the atmosphere. When exhaust air is vented from the power tool, a considerable amount of noise and particulate debris are generated, potentially causing auditory and/or respiratory damage to the operator and others located nearby.
Although earplugs and facemasks are often available, they are not always used. Numerous attempts have been made by power tool manufacturers to therefore reduce the amount of noise and particles generated by the power tool itself. These attempts include designing quieter and cleaner motors and designing power tool components that suppress noise and trap waste prior to expulsion from the power tool. For example, U.S. Pat. No. 5,418,339, which is hereby incorporated herein by reference, describes a pneumatic power tool having an exhaust port filled with a web of nonwoven fibers coated with a binder resin. Other mufflers for pneumatic power tools are disclosed in U.S. Pat. Nos. 7,216,739; 6,926,117; 6,668,971; 6,209,678; and 5,909,016, all of which are hereby incorporated herein by reference.
Despite advances in muffling technology, such as those detailed in the above-noted U.S. Patents, a continuing need exists for improvements in noise muffling systems that can reduce sound levels and remove entrained contaminates from exhausted air while eliminating or limiting negative effects on performance of the pneumatic tool.